This invention relates to apparatus for discriminating and counting white blood corpuscles and more particularly to apparatus for discriminating the types of white blood corpuscles and counting the number thereof according to the type by utilizing different absorption spectrum of different types of white blood corpuscles.
The methods of examining blood which are important for clinic chemical examinations are classified into a number of types. Most common clinical examination includes such items as the hematocrit measurement, hemoglobin measurement, counting of the number of red blood corpuscles, counting of the number of reticulocytes and discrimination and counting of the number of white blood corpuscles. Of these various items, items other than the counting of the number of reticulocytes and the discrimination and counting of the white blood corpuscles, the classification thereof being based on the pattern of blood cells, have already been automatized and are now being used in many large hospitals. However, as it is necessary to discriminate respective patterns of the blood corpuscles of both types for the purpose of counting the number of the reticulocytes and discriminating and counting the number of white blood corpuscles it is difficult to automatize these operations.
According to the conventional method of discriminating and counting the white blood corpuscles the operator discriminates and counts the number of white blood corpuscles of different types while observing a microscope. Usually, 100 to 200 white blood corpuscles per one slide are examined to determine the percentage of respective types of the white blood corpuscles, and it takes about five minutes to examine one slide. The operation of classifying and counting the number of the white blood corpuscles while adjusting the stage for the slide and the focus of the microscope requires a large labor and accompanying tiredness. For this reason, the number of the slides that can be examined by the operator in one day is only 20.
Normal white blood corpuscle cells contained in terminal venous blood which is used for standard examination are classified into neutrophils, eosinophils, basophils, lymphocytes and monocytes and then the numbers thereof are counted independently. The percentage of the number of white blood corpuscles of each type to the total number of the white blood corpuscles is relatively constant in a definite range for healthy adults, but the frequency of the appearance thereof is greatly influenced by stress, injury, diseases, poisons, radiation damage, etc. Such variation of the frequency is called as non-unique reaction and is not only effective to judge the presence or absence of a disease but also important to judge the type and degree of the diseases and to determine the method of aftercare and remedy. This increases the load of the operator so that partial or full automation of such examination is highly desirable. Such automation is also desirable to treat a number of patients in a short time not only in group diagnosis and overall health control systems but also in the screening of patients.
The following prior methods have been proposed to meet this requirement for automation. According to one method called flow system, the fact that white blood corpuscles can be stained with different colours according to their type is utilized and different methods of staining are used for different types of the white blood corpuscles for the purpose of discrimination and counting. According to another method pattern discriminating technique is utilized. Thus video signals of blood corpuscle images are formed by photographing a blood smear coated on a glass slide through a microscope and a vidicon camera, and then the video signals are analyzed for the purpose of discrimination and counting. However, according to the flow system since the discrimination and counting are performed by passing stained blood through a test tube, it is necessary to use a large quantity of blood. Moreover, when it is desired to inspect again the sample in later days it is necessary to again sample and stain blood. According to the latter method since the white blood corpuscles are classified according to the size of nuclei, pattern, density, concentration size and colour of the cellar substances it is necessary to use a plurality of large capacity memory devices for storing these information items.